Compositions containing mixtures of reducing agents and oxidizing agents which are capable of producing heat upon interaction thereof (i.e. red-ox mixtures) have long been known in the art. Thus, for example, U.S. Pat. Nos. 3,722,752 to Kenkare et al and 3,772,203 to Gray disclose cosmetic compositions which contain red-ox mixtures for self-heating purposes. U.S. Pat. No. 3,862,866 to Timmerman et al discloses a gas generator composition utilizing a red-ox mixture.
Several patents additionally disclose drain cleaning compositions containing caustic alkali, a wetting or foaming agent and certain additional ingredients which may include reducing agents or oxidizing agents. For example, U.S. Pat. No. 2,997,444 to Martin et al discloses a drain cleaning composition containing sodium hydroxide and an anti-clogging agent such as sodium sulfide or sodium thioglycolate as well as a surface active wetting agent. U.S. Pat. No. 3,697,431 to Summerfelt discloses a drain cleaning composition containing caustic alkali, a surface active wetting agent and potassium hypochlorite as an oxidizing agent. However, neither of these patents discloses compositions containing red-ox mixtures in combination with caustic alkali.
Several patents disclose compositions containing red-ox mixtures with small amounts of alkaline ingredients strictly for pH control. Examples of these are U.S. Pat. Nos. 3,804,771 to Margolis; 3,341,418 to Moses et al; and 3,632,516 to Antonelli et al.
In contrast to the above mentioned prior art, Applicant has herein unexpectedly found that improved drain cleaning performance can be obtained utilizing a drain cleaning composition containing caustic alkali in combination with red-ox mixtures. Such compositions have improved solubility characteristics which tend to prevent the formation of caustic alkaline precipitates of unreacted ingredients in the drainpipe being treated. Additionally, these formulations provide improved clog-dissolving capabilities as well as hair attack capabilities due to the improved heat generating properties of the composition.